Common fault effects on a natural refrigerant, variable-speed heat pump

To avoid continuous damage of ozone layer and deterioration of global warming, many countries have devoted to the development and application of natural refrigerant. Although CO2, an alternative refrigerant in the area of air conditioning is not the best all-temperature refrigerant, it has the lowest operating risk as compared to hydrocarbon (HCs) and ammonia.Traditional drinking fountain provides heat source through secondary energy source - electric heating; however, the heating effect is limited. Since heat pump has a high performance, this study used a carbon dioxide heat pump, which has energy-saving effect and high efficiency, to provide heat source to drinking fountains. It further assembled the drinking fountain system with carbon dioxide heat pump and analyzed its performance.

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Variable speed drive heat pump performance

Energy ◽

10.1016/0360-5442(87)90037-5 ◽

1987 ◽

Vol 12 (12) ◽

pp. 1289-1298 ◽

Cited By ~ 8

Author(s):

S.M. Jeter ◽

W.J. Wepfer ◽

G.M. Fadel ◽

N.E. Cowden ◽

A.A. Dymek

Keyword(s):

Heat Pump ◽

Variable Speed ◽

Variable Speed Drive ◽

Pump Performance

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Detailed and dynamic variable speed air source heat pump water heater model: Combining a zonal tank model approach with a grey box heat pump model

International Journal of Refrigeration ◽

10.1016/j.ijrefrig.2018.05.022 ◽

2018 ◽

Vol 92 ◽

pp. 55-69 ◽

Cited By ~ 4

Author(s):

Kevin Ruben Deutz ◽

Gaspard-Louis Charles ◽

Odile Cauret ◽

Romuald Rullière ◽

Philippe Haberschill

Keyword(s):

Heat Pump ◽

Variable Speed ◽

Dynamic Variable ◽

Water Heater ◽

Tank Model ◽

Air Source Heat Pump ◽

Heat Pump Water Heater ◽

Model Combining ◽

Model Approach

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Development of an empirical model of a variable speed vapor injection compressor used in a Modelica-based dynamic model of a residential air source heat pump

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/90/1/012031 ◽

2015 ◽

Vol 90 ◽

pp. 012031

Author(s):

Bertrand Dechesne ◽

Stephane Bertagnolio ◽

Vincent Lemort

Keyword(s):

Dynamic Model ◽

Heat Pump ◽

Empirical Model ◽

Variable Speed ◽

Air Source Heat Pump ◽

Vapor Injection

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Dehumidification performance of a variable speed heat pump and a single speed heat pump with and without dehumidification capabilities in a warm and humid climate

Energy Reports ◽

10.1016/j.egyr.2020.06.024 ◽

2020 ◽

Vol 6 ◽

pp. 1696-1701

Author(s):

Koukouni P. Kone ◽

Nelson Fumo

Keyword(s):

Heat Pump ◽

Variable Speed ◽

Humid Climate

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Energy Savings through Variable Speed Compressor Heat Pump Systems

Energy Procedia ◽

10.1016/j.egypro.2011.12.1098 ◽

2012 ◽

Vol 14 ◽

pp. 1337-1342 ◽

Cited By ~ 24

Author(s):

R.S. Adhikari ◽

N. Aste ◽

M. Manfren ◽

D. Marini

Keyword(s):

Heat Pump ◽

Energy Savings ◽

Variable Speed

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ANALYSIS OF THE THERMODYNAMICAL EFFICIENCY OF AN AIR HANDLING UNIT WITH A HEAT PUMP / VĖDINIMO ĮRENGINIO SU ŠILUMOS SIURBLIU TERMODINAMINIO EFEKTYVUMO TYRIMAS

Mokslas - Lietuvos ateitis ◽

10.3846/mla.2012.79 ◽

2012 ◽

Vol 5 (4) ◽

pp. 493-498 ◽

Cited By ~ 4

Author(s):

Vytautas Martinaitis ◽

Paulius Bareika ◽

Violeta Misevičiūtė

Keyword(s):

Heat Pump ◽

Heat Recovery ◽

Thermodynamic Potential ◽

Energy Analysis ◽

Ventilation System ◽

Point Of View ◽

Thermodynamic Efficiency ◽

Variable Speed ◽

Air Handling Unit ◽

Heat Demand

This paper evaluates the seasonal thermodynamic efficiency of the air-to-air heat pump used for a heat recovery ventilation system and several modulations of compressors affecting the thermodynamic efficiency of the heat pump. A variable speed and on/off-type compressors have been selected. In order to evaluate the thermodynamic potential of the device, energy analysis has been performed. Along with modelling the operation of the air handling unit during the cold time of the year, variations in the thermodynamic efficiency or different modulation compressors have been compared. The obtained results have shown that the use of a few simple compressors causes a decrease in the seasonal parameters of the heat pump: heat generated by a condenser is 5% lower compared to the use of variable speed compressors and therefore the seasonal coefficient of the performance (COP) of the heat pump decreases by 5%. Possible improvement on the heat pump can be provided changing the compressor into variable speed or modulatory equipment, which allows adjusting to heat demand and thus increases the seasonal efficiency of the system from a thermodynamic point of view. Santrauka Straipsnyje vertinamas oras-oras šilumos siurblio, naudojamo vėdinimo sistemos šilumogrąžai, sezoninis termodinaminis naudingumas ir kelios kompresorių, turinčių įtakos termodinaminiam šilumos siurblio naudingumui, moduliacijos. Analizei pasirinkti kintamo greičio ir įjungiamo / išjungiamo tipo kompresoriai. Siekiant įvertinti įrenginio termodinaminį potencialą atliekama ekserginė analizė. Modeliuojant vėdinimo įrenginio veikimą šaltuoju metų laiku, lyginama, kaip kinta skirtingų moduliacijų kompresorių termodinaminis naudingumas. Tyrimo rezultatai rodo, kad naudojant kelis paprastus kompresorius sezoniniai šilumos siurblio parametrai krenta: kondensatoriaus atiduodamas šilumos srautas yra 5 % mažesnis, lyginant su kintamo veikimo kompresorių naudojimu, be to, 5 % sumažėja sezoninis šilumos siurblio efektyvumo koeficientas (COP). Šilumos siurblį galima tobulinti kompresorių keičiant į kintamo greičio arba moduliacinį, kuris leistų prisitaikyti prie šilumos poreikio ir tokiu būdu termodinaminiu požiūriu pagerintų sezoninį sistemos efektyvumą.

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Vortex Tube Expansion Transcritical CO2 Heat Pump Cycle

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.190-191.1340 ◽

2012 ◽

Vol 190-191 ◽

pp. 1340-1344 ◽

Cited By ~ 3

Author(s):

Ying Fu Liu ◽

Chun Jing Geng ◽

Guang Ya Jin

Keyword(s):

Heat Pump ◽

Ozone Depletion ◽

System Performance ◽

Vortex Tube ◽

Outlet Temperature ◽

Throttle Valve ◽

Refrigerant Alternatives ◽

Natural Refrigerant ◽

Tube Expansion ◽

Better Than

The application of natural refrigerant CO2 is of great significance to reduce the greenhouse effect and ozone depletion. Transcritical CO2 heat pump cycle is presently an important aspect of natural refrigerant alternatives research. In this paper, a vortex tube expansion transcritical CO2 heat pump cycle is established and compared to that of the transcritical CO2 refrigeration cycle with throttle valve. Thermodynamic analysis results indicate that the system performance of vortex tube expansion transcritical CO2 heat pump cycle is better than the transcritical CO2 heat pump cycle with throttle valve, and the COPh improvement is 5.8%~13.9% at given conditions. The gas-cooler outlet temperature has a great impact on the system performance, there is a higher COPh improvement when the cycle at lower evaporation temperature or higher gas-cooler outlet temperature.

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